Quantum dots cause acute systemic toxicity in lactating rats and growth restriction of offspring

Abstract

The in vivo toxicity of QDs in animals has been broadly studied; however, their reproductive toxicity towards lactating rodents is currently unknown. This study therefore aims to assess the potential toxicity against dams and offspring after postnatal QD exposure at two doses (5 and 1 nmol per rat) and unravel whether QDs can translocate to pups via breastfeeding. The dose-dependent systemic toxicity of QDs in dams was observed by examining the body weight, hematology, biochemistry, histopathological changes, and sex hormone levels. It was found that the QDs primarily accumulated in the liver and spleen of dams at 1 day post injection (dpi), but the highest concentrations were found in the kidneys at 18 dpi. A few QDs were detected in breast milk and stomach and intestine of pups; this suggested that the QDs were transmitted to breast milk via blood circulation and then transferred to pups via breastfeeding. High-dose QDs induced severe growth inhibition and a 71.08% offspring mortality, while pups showed growth restriction within 90 dpi in the low-dose group. Moreover, the hematology, biochemistry, and histology results showed limited chronic toxicity against offspring in the long term. This study provides a theoretical foundation for the exposure assessment of nanomaterials in lactating animals and for the advancement of QDs in the biomedical field.

Three-Dimensional Quantitative Co-Mapping of Pulmonary Morphology and Nanoparticle Distribution with Cellular Resolution in Nondissected Murine Lungs

“…17 Thus, distribution, localization and dosimetry of NPs within whole organs and even whole organisms are of paramount importance for understanding the link between physico-chemical 5 characteristics of NP and associated health effects. [18][19][20] Currently available in vivo imaging techniques offer gross anatomical distribution of NPs using e.g. X-ray computed tomography, magnetic resonance imaging (MRI), in vivo imaging system (IVIS), positron emission tomography (PET), single photon emission computed tomography (SPECT), and photoacoustic imaging.…”

“…To achieve this goal, several common ex vivo assays, including transmission electron microscopy (TEM), 2D stereological methods, flow cytometry, and ICP-MS were applied to examine and/or quantify NP localization and distribution at cellular resolution, but the information on 3D tissue architecture was totally destroyed. [20][21][22] Currently, no available technique is able to both visualize the spatial distribution of NPs and quantify their accumulated dose in entire organs (e.g. lungs) with cellular resolution.…”

A review of hepatic nanotoxicology – summation of recent findings and considerations for the next generation of study designs

“…Histopathological analysis also demonstrated severe hepatic cellular apoptosis, necrosis, cytolysis, blurred hepatic sinus borderline, as well as a loss of the integrity and morphology of hepatic lobules in exposed animals at day 1 post exposure. Once again, all of these changes had largely resolved by day 18 post exposure (Yang et al 2018a). Evidence thus indicates the remarkable ability of liver to regenerate.…”

“…In vitro studies Based upon the advancements in hepatic nanotoxicology, it is reasonable to state for the majority of NMs studied in the liver, any meaningful NM-induced adverse effects in the liver occurred at acute time points with the potential to resolve (Kermanizadeh et al 2017a(Kermanizadeh et al , 2017bYang et al 2018a), and effects of more relevance would only take place after long-term exposure in man (further discussed below). Therefore, it is essential to establish more advanced, physiologically relevant in vitro assessment tools for improved prediction of the adverse effects attributed to life-time NM exposure in humans (as discussed above the considerable progress in the development of multi-cellular primary organoids over the last few years has been a great success with this regard).…”

“…(1) As discussed above, all in vivo hepatic hazard assessment studies need to be designed and executed with intermittent repeated dosing and most importantly with recovery periods (Bahamonde et al 2018;Yang et al 2018aYang et al , 2018b. Such a protocol enables either accumulation or clearance of NMs, manifestation of adverse effects and potential for organ recovery to be identified, leading to a more realistic understanding of the toxic potential of NMs.…”